Battery module with improved vent structure

Abstract

The present invention provides a battery module structure that includes a battery cell stack formed by stacking a plurality of pouch-shaped battery cells and metal plates in the width direction, a U-frame that is open at the top, front, and rear and that houses the battery cell stack, a pair of end plates that cover the front and rear of the U-frame, and a top plate that covers the top of the U-frame, in which vent paths are improved to prevent heat propagation.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0182327 dated December 22, 2022, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module structure that has improved thermal runaway delay and venting performance in a battery module that houses a plurality of pouch-type battery cells. [Background technology]

[0003] Secondary batteries, which are easy to apply to various products and have electrical properties such as high energy density, are commonly used not only in portable devices but also in electric vehicles or hybrid vehicles powered by electrical sources, power storage devices, etc. These secondary batteries are attracting attention as a new energy source not only because they have the primary advantage of dramatically reducing the use of fossil fuels, but also because they are environmentally friendly and improve energy efficiency by not producing any by-products from energy use.

[0004] While small mobile devices use one or two or three battery cells per device, medium to large devices such as automobiles require high output and large capacity, so medium to large battery modules, which electrically connect multiple battery cells, are used.

[0005] Since it is preferable to manufacture medium- to large-sized battery modules with small size and weight if possible, prismatic batteries and pouch-shaped batteries, which can be stacked with high density and have a small weight relative to their capacity, are mainly used as battery cells for medium- to large-sized battery modules.

[0006] 1 and 2 show the structure of a pouch-type battery cell and how venting occurs in the battery cell, respectively. Referring to these figures, a pouch-type battery cell 11 comprises an electrode assembly and a metallic pouch that surrounds and seals the electrode assembly. The pouch is fused and sealed at first seal portions 111 provided at both longitudinal ends and at a second seal portion 112 provided at one vertical end. An electrode lead 113 extends from the electrode assembly and protrudes outside the pouch through the first seal portion 111.

[0007] 3 and 4 are exploded and perspective views, respectively, showing the structure of a typical battery module. Referring to these drawings, the battery module comprises a battery cell stack 1 in which a plurality of battery cells 11 are stacked, bus bar frames 2 connected to both longitudinal ends of the battery cell stack 1, and a housing 3 that accommodates the battery cell stack 1. The housing 3 comprises a U-frame 31 that is open at the top, front, and rear, a pair of end plates 32 that cover the front and rear of the U-frame 31, and a top plate 33 that covers the top of the U-frame. The U-frame 31, the end plates 32, and the top plate 33 can be assembled together by welding.

[0008] The battery cell 11 may ignite due to a short circuit, impact, heat, etc. In this case, a large amount of gas and thermal energy may be emitted from the battery cell 11. If this gas and thermal energy is transmitted to other adjacent battery cells in the battery module, thermal runaway may occur, causing a chain reaction of fires between the battery cells. The gas and thermal energy may be emitted through both ends in the length direction and one end in the height direction of the battery cell 11, where the first sealing portion 111 and the second sealing portion 112 are provided.

[0009] A plurality of the battery modules may be assembled to form a battery pack. In this case, gas and heat energy generated from the battery module may be transferred to the adjacent battery module. Alternatively, gas and heat energy generated from the adjacent battery module may be transferred to the battery module. In this case, thermal runaway may occur within the battery pack. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention was devised against the background of the conventional technology described above, and aims to provide a battery module structure that prevents heat transmission between battery cells housed within a battery module and between battery modules housed within a battery pack.

[0011] Another object of the present invention is to provide a battery module structure that allows high-temperature gas and thermal energy generated in the event of a battery cell ignition to be quickly discharged in the intended direction.

[0012] A further technical object of the present invention is to provide a battery module structure that prevents the discharged high-temperature gas and thermal energy from re-entering.

[0013] The technical object of the present invention is not limited to the above-mentioned objects, and other unmentioned objects and advantages of the present invention can be understood from the following description and can be more clearly understood from the examples of the present invention. Furthermore, it can be easily understood that the objects and advantages of the present invention can be achieved by the means and combinations thereof set forth in the claims. [Means for solving the problem]

[0014] In order to solve the above problems, the present invention provides a battery module structure including: a battery cell stack formed by stacking a plurality of pouch-shaped battery cells and metal plates in the width direction; a U-frame that is open at the top, front, and rear and that houses the battery cell stack; a pair of end plates that cover the front and rear of the U-frame; and a top plate that covers the top of the U-frame, wherein the top plate has a plurality of vent holes and the metal plate has a plurality of lid portions that correspond to the vent holes, and each of the lid portions protrudes upward through the top plate and is bent to one side in the width direction to cover at least a portion of the area of ​​the vent hole.

[0015] The battery cell stack may include a plurality of unit cell stacks each including a plurality of the battery cells.

[0016] The metal plate may be stacked on the other widthwise side of each of the battery cells or each of the unit cell stacks. In this case, the metal plate may be stacked directly on the other widthwise side of the battery cells, or may be stacked with an additional layer interposed between the metal plate and the battery cells. Each stack including one battery cell or one unit cell stack and one metal plate may be a unit stack that forms the battery cell stack.

[0017] One or more vent holes may be provided on each of the battery cells or the unit cell stack. When a plurality of vent holes are provided on the battery cell or the unit cell stack, the vent holes may be spaced apart from one another in the length direction or the width direction. This allows the top plate to have a grill-like shape in the portions where no vent holes are provided, thereby ensuring necessary rigidity in the length direction and the width direction.

[0018] In this case, the lid portions may be provided to correspond to the vent holes. That is, the lid portions may be provided at positions corresponding to the positions of the vent holes and in a number corresponding to the number of the vent holes.

[0019] The battery cell stack may include a heat insulating pad stacked together with the battery cells and the metal plate. The heat insulating pad may be made of a heat insulating material and may be stacked in any position as long as it is stacked together with the battery cells and the metal plate to prevent heat transfer between the battery cells or between the battery module and other adjacent battery modules. For example, the heat insulating pad may be stacked on one or the other widthwise side of the metal plate, or may be interposed between any two widthwise adjacent battery cells. Even when a plurality of battery cells are assembled to form the unit cell stack, the heat insulating pad may be interposed between the battery cells in the unit cell stack and stacked together.

[0020] The heat insulating pad may be made of a compressible material, which can prevent heat transfer and absorb width tolerances of the metal plate and the battery cells and deformation due to swelling.

[0021] The battery module may include a heat-resistant filler that fills at least a portion of the space between the battery cell stack and the end plate. In this case, the battery cells have first seals at both longitudinal ends, and the heat-resistant filler can cover the first seals. This prevents gas and thermal energy from escaping longitudinally in the event of a fire in the battery cells. The heat-resistant filler may include heat-resistant silicone. However, the heat-resistant filler is not limited to any particular material, and may be made of any material that is heat-resistant and can be filled.

[0022] Each of the lid portions may be bent to one side in the width direction and then a portion of the lid portion may be welded to the top plate. By welding the lid portion to the top plate, structural stability between the battery cell stack and the top plate may be improved.

[0023] The lid portion may include a first lid portion that penetrates the top plate through a predetermined first vent hole and covers a second vent hole that is adjacent to the first vent hole in the width direction.

[0024] The lid portion may include a second lid portion that penetrates the top plate through a slit provided in the top plate and covers the vent hole adjacent to the slit in the width direction. The slit may be provided adjacent to the other widthwise end of the top plate, and the lid portion that protrudes from the metal plate that is located at the outermost edge on the other widthwise side of the battery cell stack may be the second lid portion.

[0025] The first lid portion may contact the top plate at one side end in the width direction of the first vent hole, and the second lid portion may contact the top plate at one side end in the width direction of the slit.

[0026] The thickness of the metal plate can be selected appropriately so that it can be bent when a bending moment equal to or greater than a predetermined value is applied, but will not deform when a bending moment equal to or less than the predetermined value is applied. For example, the metal plate can have a thickness of 1 mm to 2 mm. Preferably, the metal plate can have a thickness of 1.4 mm to 1.6 mm.

[0027] When the battery cell stack is housed in the U-frame, the battery cells may have second sealing portions at one end in the height direction, and the battery cell stack may be arranged so that the second sealing portions face upward. In this case, the second sealing portion may be provided along one long side in the width direction of one surface of the battery cells in the height direction.

[0028] In the battery module according to the present invention, if a battery cell ignites, gas and heat energy can be discharged upward. The gas and heat energy discharged upward can cause the cover to bend outward and open the vent hole, allowing the gas and heat energy to be quickly discharged outside the battery module. The vent holes located on other battery cells that are not igniting are covered by the cover, preventing the gas and heat energy from re-entering the battery module. [Effects of the Invention]

[0029] The present invention can provide a battery module structure in which heat is insulated and shielded between each battery cell and / or unit cell stack, thereby preventing heat transfer due to conduction between battery cells.

[0030] According to the present invention, it is possible to provide a battery module structure in which, when a battery cell ignites, high-temperature gas and thermal energy are guided to be discharged upward and can be discharged independently for each battery cell and / or unit cell stack.

[0031] Another advantage of the battery module according to the present invention is that it prevents the inflow and re-inflow of high-temperature gas and thermal energy discharged from other battery cells and / or unit cell stacks and other battery modules, thereby preventing heat transfer between battery cells and battery modules.

[0032] In addition, the present invention can achieve various other effects, which will be explained in each embodiment, or explanations of effects that can be easily inferred by ordinary skilled artisans will be omitted. [Brief explanation of the drawings]

[0033] [Figure 1] FIG. 1 is a diagram showing the structure of a pouch-type battery cell. [Figure 2] FIG. 1 illustrates how venting occurs in a battery cell. [Figure 3]FIG. 1 is an exploded perspective view showing the structure of a typical battery module. [Figure 4] FIG. 1 is a perspective view showing the structure of a typical battery module. [Figure 5] 1 is a diagram illustrating a stack structure of a unit cell stack according to an embodiment of the present invention; [Figure 6] 1 is a diagram showing a stacked structure of a battery cell, a metal plate, and a heat insulating pad according to an embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view of the battery cell stack of FIG. [Figure 8] 1 is an exploded perspective view showing a battery module according to an embodiment of the present invention before a top plate is assembled thereto; [Figure 9] 1 is a perspective view illustrating a battery module according to an embodiment of the present invention before a top plate is assembled thereto; [Figure 10] 10 is a diagram showing a cross section of the battery module of FIG. 9 and the arrangement of a heat-resistant filler. [Figure 11] FIG. 2 is a diagram showing a state before a top plate is assembled to a battery module according to an embodiment of the present invention. [Figure 12] 10 is a view showing a state after a top plate is assembled to a battery module according to an embodiment of the present invention. FIG. [Figure 13] FIG. 13 is a cross-sectional view of the battery module of FIG. [Figure 14] 1 is a diagram showing a battery module according to an embodiment of the present invention; [Figure 15] FIG. 15 is a cross-sectional view of the battery module of FIG. [Figure 16] FIG. 16 is a partially enlarged view of a main part of FIG. 15. [Figure 17] 1A and 1B are diagrams illustrating how venting occurs in a battery module according to an embodiment of the present invention. [Figure 18] 1 is a diagram showing a battery pack incorporating another battery module according to an embodiment of the present invention; [Figure 19] FIG. 20 is a diagram showing a car incorporating the battery pack of FIG. 18. DETAILED DESCRIPTION OF THE INVENTION

[0034] The above-mentioned objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily implement the technical concept of the present invention. In describing the present invention, if a detailed description of known technologies related to the present invention is deemed to obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings are used to indicate the same or similar components.

[0035] Although terms such as "first" and "second" are used to indicate various components, it is understood that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a first component may also be a second component.

[0036] Throughout the specification, unless otherwise specified, each element may be singular or plural.

[0037] Hereinafter, when an arbitrary structure is arranged "on top (or bottom)" of a component or "above (or below)" a component, it means that the arbitrary structure is not only arranged in contact with the upper surface (or lower surface) of the component, but also that other structures may be interposed between the component and the arbitrary structure arranged above (or below) the component.

[0038] Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the components may be directly coupled or connected to each other, but that other components may be "intervening" between the components, or that each component may be "coupled," "coupled," or "connected" via other components.

[0039] As used herein, singular expressions include plural expressions unless the context clearly indicates otherwise. Terms such as "comprise" or "include" in this application should not be interpreted as including all of the multiple components or multiple steps described in the specification, but should be interpreted as meaning that some of the components or some of the steps may not be included, or that additional components or steps may be included.

[0040] In the entire specification, "A and / or B" means A, B or A and B unless otherwise specified, and "C to D" means C or more and D or less unless otherwise specified.

[0041] The present invention provides a battery module structure that includes a battery cell stack formed by stacking a plurality of pouch-shaped battery cells and metal plates in the width direction, a U-frame that is open at the top, front, and rear and that houses the battery cell stack, a pair of end plates that cover the front and rear of the U-frame, and a top plate that covers the top of the U-frame, in which vent paths are improved to prevent heat propagation.

[0042] The means for solving the problems of the present invention can be applied to a battery module and a battery pack having a structure in which a plurality of battery cells having a certain thickness are stacked on top of each other and housed inside a single housing.

[0043] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

[0044] 1 and 2 show the structure of a pouch-type battery cell and how venting occurs in the battery cell, respectively. Referring to these figures, a battery cell 11 may be formed by sealing a pouch of sheet material that houses an electrode assembly.

[0045] The electrode assembly may be formed by repeatedly stacking a plurality of positive and negative electrodes with a separator interposed therebetween, and an electrode lead 113 may extend from the electrode assembly and protrude outside the pouch.

[0046] The pouch may be made of a metal material. The pouch may be coated with a synthetic resin layer for insulation inside and outside. The pouch may contain the electrode assembly, be folded in half, and be sealed by fusing the inner insulating layer. However, the pouch may have a different material and structure from the above materials, and may be sealed in any other manner.

[0047] The pouch may be sealed with a first sealing portion 111 provided at both ends in the length direction and a second sealing portion 112 provided at one end in the height direction. The electrode lead 113 may protrude to the outside of the pouch through the first sealing portion 111. The second sealing portion 112 may be provided along one long side in the width direction of one surface in the height direction of the battery cell 11. The second sealing portion 112 may be folded to one side in the width direction and then re-sealed with tape.

[0048] The battery cell 11 may catch fire due to a short circuit, impact, heat, etc. At this time, a large amount of gas and heat energy may be emitted from the battery cell 11. The gas and heat energy may be emitted through both ends in the length direction and one end in the height direction of the battery cell 11 where the first seal portion 111 and the second seal portion 112 are provided.

[0049] 6 shows a stacked structure of a battery cell, a metal plate, and a heat insulating pad according to an embodiment of the present invention. Referring to this figure, a metal plate 12 may be stacked on the other widthwise side of the battery cell 11. In this case, the metal plate 12 may be stacked on the other widthwise side of the battery cell 11 with an additional layer interposed between the metal plate 12 and the battery cell 11.

[0050] Alternatively, a plurality of the battery cells 11 may be stacked to form a unit cell stack, and the metal plate 12 may be stacked on the other side of the unit cell stack in the width direction. In this case, the plurality of battery cells 11 and the metal plate 12 may be stacked with an additional layer interposed between them.

[0051] The metal plate 12 may include a lid portion 121 protruding upward from one end in the height direction of the metal plate 12. A plurality of the lid portions 121 may be provided. The plurality of lid portions 121 may be arranged in a longitudinal direction, and in particular, may be arranged spaced apart in the longitudinal direction.

[0052] The battery cells 11 and the metal plate 12 may be stacked together with an insulating pad 13 made of an insulating material. The insulating pad 13 may be interposed between one battery cell 11 and another adjacent battery cell 11, or may be stacked on one or the other widthwise side of the battery cell 11 or the metal plate 12. The metal plate 12 and the pouches of the battery cells 11 are made of a metal material and have a high heat conduction rate, so providing the insulating pad 13 can slow down the heat propagation rate between the battery cells 11.

[0053] The heat insulating pad 13 may be made of a compressible material. In this case, when deformation due to swelling occurs in the battery cells 11 or when there is a tolerance in the stack structure of the battery cells 11, the heat insulating pad 13 can absorb the swelling and the tolerance.

[0054] According to one embodiment of the present invention, the heat insulating pad 13 may be laminated on the other widthwise side of each of the battery cells 11. The metal plate 12, on which the cover portions 121 are arranged at intervals in the lengthwise direction, may be laminated on the other widthwise side of the heat insulating pad 13. That is, each of the battery cells 11 may be configured as one unit laminate in which the heat insulating pad 13 and the metal plate 12 are sequentially laminated on the other widthwise side of the battery cell 11.

[0055] In one modified example, a plurality of the battery cells may be stacked with the insulating pad interposed therebetween to form a unit cell stack. The insulating pad may be stacked on the other side in the width direction of each unit cell stack. The metal plate, on which the cover portions are arranged at intervals in the length direction, may be stacked on the other side in the width direction of the insulating pad. That is, each unit cell stack may be configured as a single unit stack, with the insulating pad and the metal plate sequentially stacked on the other side in the width direction.

[0056] In the following embodiment, an example is given in which each unit laminate body includes one battery cell 11, but it can be easily understood that the means for solving the problem of the present invention can be applied as is to a case in which each unit laminate body includes a plurality of battery cells 11.

[0057] Fig. 6 shows a battery cell stack according to one embodiment of the present invention, and Fig. 7 shows a cross-section of the battery cell stack of Fig. 6. Referring to these drawings, a plurality of the battery cells 11, the metal plates 12, and / or the heat insulating pads 13 may be stacked in the width direction to form the battery cell stack 1. The battery cell stack 1 may also be formed by repeatedly stacking a plurality of the unit stack bodies.

[0058] A pair of bus bar frames 2 may be connected to both ends of the battery cell stack 1 in the longitudinal direction.

[0059] The battery cell stack 1 according to one embodiment of the present invention may be formed by repeatedly stacking unit stacks, each of which has one battery cell 11, one heat insulating pad 13, and one metal plate 12 stacked on the other side in the width direction, and a pair of bus bar frames 2 may be connected to both ends of the battery cell stack 1 in the length direction.

[0060] In one variation, the battery cell stack 1 may further include the heat insulating pad 13 stacked on the outermost edge of one and / or the other side in the width direction.

[0061] 8 and 9 are exploded and perspective views showing a battery module according to an embodiment of the present invention before a top plate is assembled. Referring to these drawings, the battery cell stack 1 can be housed in a housing 3 to form a battery module.

[0062] The battery cell stack 1 may be housed in the housing 3 with the second sealing portion 112 facing upward. As the second sealing portion 112 faces upward, the main discharge direction of gas and heat energy emitted from the battery cells 11 may face upward. In this case, the second sealing portion 112 may be positioned offset to one side in the width direction relative to the width center of the battery cells 11.

[0063] The housing 3 may include a U-frame 31 that is open at the top, front, and rear, and a pair of end plates 32 that cover the front and rear of the U-frame 31, respectively.

[0064] The U frame 31 and the end plates 32 may be joined together to form the housing. The U frame 31 and the end plates 32 may each include a metal material. In this case, the U frame 31 and the end plates 32 may be welded together. However, the materials and joining method of the U frame 31 and the end plates 32 are not limited thereto, and the U frame 31 and the end plates 32 may be made of a material other than a metal material, and may be joined together by a method other than welding.

[0065] A battery module according to an embodiment of the present invention may include the housing 3 including the U-frame 31 and the pair of end plates 32, and the battery cell stack 1 housed in the housing 3 with the second sealing portion 112 facing upward. In this case, the facing direction of the second sealing portion 112 and the protruding direction of the cover portion 121 may be aligned upward.

[0066] 10 shows a cross section of the battery module of FIG. 9 and the arrangement of a heat-resistant filler. Referring to FIG. 10, the bus bar frame 2 may include slits 21 and bus bars 22. The electrode leads 113 may pass through the slits 21 and be welded to the bus bars 22. The bus bars 22 may connect the electrode leads 113 to each other in series or in parallel.

[0067] An empty space may be formed between the battery cell stack 1 and the end plate. At least a portion of the empty space may be filled with a heat-resistant filler 4. That is, the heat-resistant filler 4 may fill at least a portion of the empty space formed between the battery cell stack 1 and the bus bar frame 2, and between the bus bar frame 2 and the end plate.

[0068] The heat-resistant filler 4 may be provided to cover the first seal portion 111 from which the electrode lead 113 protrudes. This prevents gas and heat energy from escaping through the first seal portion 111 when the battery cell 11 catches fire.

[0069] In this case, preferably, when the battery cell 11 ignites, the direction in which gas and thermal energy are discharged can be limited to one side in the height direction, i.e., upward. In other words, in this case, both sides in the width direction and the other side in the height direction of the battery cell 11 are surrounded and sealed by the pouch, and both sides in the length direction of the battery cell 11 are sealed by the heat-resistant filler 4 covering the first seal portion 111. When the battery cell 11 ignites, gas and thermal energy can be discharged only through the second seal portion 112 provided on one side in the height direction. In this case, the gas discharge paths (vent paths) of the battery cells 11 are formed independently within the housing 3, and each battery cell 11 can have its own vent path that is not shared with other battery cells.

[0070] The heat-resistant filler 4 may contain heat-resistant silicone, but may be made of any material as long as it has heat resistance and can fill the empty space and cover the first seal portion 111.

[0071] According to one embodiment of the present invention, the heat-resistant filler 4 may include a heat-resistant silicone material and may be filled into the empty spaces formed between the battery cell stack 1 and the bus bar frame 2 and between the bus bar frame 2 and the end plate, thereby completely covering the first sealing portion 111.

[0072] 11 and 12 respectively show a battery module according to an embodiment of the present invention before and after a top plate is assembled, and FIG. 13 shows a cross section of the battery module of FIG. 12. Referring to these drawings, the housing 3 may include a top plate 33 that covers the upper part of the U frame 31. The top plate 33 may include a metal material. The top plate 33 may be welded to the U frame 31. However, the material of the top plate 33 and the manner of joining it to the U frame 31 are not limited thereto, and the top plate 33 may be made of a material other than a metal material, and may be joined to each other by a method other than welding.

[0073] The top plate 33 may be provided with a vent hole 331 that passes through the top plate 33 from top to bottom. A plurality of the vent holes 331 may be provided.

[0074] One or more vent holes 331 may be provided on each of the battery cells 11. When a plurality of vent holes 331 are provided on each of the battery cells 11, the vent holes 331 may be arranged spaced apart from one another in the longitudinal direction. In this case, the vent holes 331 may be arranged in a lattice pattern, leaving a grill shape on the top plate 33. This allows the top plate 33 to ensure appropriate rigidity in both the width direction and the length direction despite the vent holes 331.

[0075] Alternatively, one or more vent holes 331 may be provided on each of the unit cell stacks. When a plurality of vent holes 331 are provided on each of the unit cell stacks, the vent holes 331 may be arranged spaced apart from one another in the length direction or the width direction. In this case, the vent holes 331 may be arranged in a lattice pattern, leaving a grill shape on the top plate 33. This allows the top plate 33 to ensure appropriate rigidity in both the width direction and the length direction despite the vent holes 331.

[0076] In this case, the vent holes 331 and the lids 121 may be provided at positions corresponding to each other or in the same number. However, in another case, the number of vent holes 331 may be greater than the number of lids 121, and one lid 121 may be provided at a position corresponding to a plurality of vent holes 331. Alternatively, the number of lids 121 may be greater than the number of vent holes 331, and a plurality of lids 121 may be provided corresponding to one vent hole 331.

[0077] The lid 121 may penetrate the top plate 33 and protrude upward. The top plate 33 may be provided with a slit 332 through which the lid 121 can penetrate. The slit 332 may be provided by separately punching, or may be provided without being joined to the joint between the top plate 33 and the U-frame 31. The lid 121 may penetrate the top plate 33 through the vent hole 331, or may penetrate the top plate 33 through the slit 332.

[0078] The battery module according to an embodiment of the present invention may include the top plate 33, which may be made of a metal material and welded to the U-frame 31. The top plate 33 may include a plurality of vent holes 331 spaced apart in the longitudinal direction at positions and in numbers corresponding to the cover portions 121 on each of the battery cells 11, and the slits 332 spaced apart in the longitudinal direction and adjacent to the other widthwise end of the top plate 33. In this case, each of the cover portions 121 may penetrate the top plate 33 and protrude upward via one of the slits 332 and the vent hole 331.

[0079] Fig. 14 shows a battery module according to an embodiment of the present invention, and Fig. 15 shows a cross-section of the battery module of Fig. 14. Referring to these drawings, the cover 121 may penetrate the top plate 33, protrude upward, and then be bent to one side in the width direction.

[0080] The lids 121 can be folded to cover at least a portion of the vent holes 331. As a result, all of the vent holes 331 can be covered by at least one of the lids 121. In this case, it is not necessary for one vent hole 331 to be covered by one lid 121. In addition, it is preferable that the vent holes 331 are not covered by the lids 121 and have a predetermined area that is open upward. This is to prevent a sudden increase in the pressure resistance of the housing 3 by allowing a small amount of gas generated from the battery cells 11 to be discharged before a full-scale thermal runaway or fire begins.

[0081] According to one embodiment of the present invention, each of the lids 121 may penetrate the top plate 33, protrude upward, and then bend inward in the width direction to cover a portion of any one of the vent holes 331. In this case, the vent hole 331 may have a predetermined area that is not covered by the lid 121 and is open upward.

[0082] FIG. 16 is a partially enlarged view of the main part of FIG.

[0083] The lid portion 121 may include a first lid portion 121a penetrating the top plate 33 through the vent hole 331. The first lid portion 121a may pass through a predetermined first vent hole 331a to cover a second vent hole 331b adjacent to the first vent hole 331a in the width direction. In this case, the first vent hole 331a may be determined differently for each of the first lid portions 121a, and accordingly, the second vent hole 331b may also be determined differently for each of the first lid portions 121a. For example, any of the vent holes may be a first vent hole in one first lid portion and a second vent hole in another first lid portion.

[0084] In this case, the first cover 121a may contact the top plate 33 at one widthwise end of the first vent hole 331a. In other words, the first cover 121a may be bent to one widthwise side with the one widthwise end of the first vent hole 331a, through which the first cover 121a passes, as a boundary. If a roller is used to bend the first cover 121a, the roller may apply a force to the first cover 121a toward one widthwise side, and the one widthwise end of the first vent hole 331a may provide a corresponding reaction force, thereby bending the first cover 121a to one widthwise side. In this case, for structural safety, it is preferable that the first cover 121a simultaneously contact the inner surface of the first vent hole 331a adjacent to the one widthwise end of the first vent hole 331a and the upper surface of the top plate 33.

[0085] The top plate 33 may include a second lid portion 121b that penetrates the top plate 33 through the slit 332. The second lid portion 121b passes through the slit 332 and can cover the vent hole 331 adjacent to the slit 332 in the width direction.

[0086] In this case, the second cover 121b may contact the top plate 33 at one widthwise end of the slit. In other words, the second cover 121b may be bent to one widthwise side using one widthwise end of the slit 332, through which the second cover 121b passes, as a boundary. If a roller is used to bend the second cover 121b, the roller may apply a force to the second cover 121b toward one widthwise side, and the one widthwise end of the slit 332 may provide a corresponding reaction force, thereby bending the second cover 121b to one widthwise side. In this case, for structural safety, it is preferable that the second cover 121b simultaneously contact the inner surface of the slit 332 adjacent to the one widthwise end of the slit 332 and the upper surface of the top plate 33.

[0087] After being bent, a portion of the lid portion 121 may be joined to the top plate 33. For example, a portion of the lid portion 121 adjacent to the distal end side and / or the proximal end side of the bent portion may be welded to the inner surface of the vent hole 331 or the slit 332 penetrating the lid portion 121 and / or the upper surface of the top plate 33. The joining may be by welding. By joining the lid portion 121 to the top plate 33, the safety of the positional relationship between the lid portion 121 and the top plate 33 may be improved.

[0088] According to one embodiment of the present invention, the cover 121 may include a second cover 121b that protrudes from the metal plate 12 provided at the outermost edge on the other side in the width direction, penetrates the top plate 33 through the slit 332, and protrudes upward, and the first cover 121a that is the other cover 121 except for the second cover 121b, penetrates the top plate 33 through any one of the vent holes 331, and protrudes upward. In this case, the first cover 121a and the second cover 121b may contact one side end of the vent hole 331 and the slit 332 in the width direction, and a portion thereof may be welded to the top plate 33.

[0089] 17 illustrates venting in a battery module according to an embodiment of the present invention. When any battery cell 11 catches fire, a large amount of gas and heat energy may be released upward from the battery cell 11. The gas and heat energy may be released through the second seal 112 located on one long side of the upper surface of the battery cell 11 in the width direction.

[0090] In this case, each of the battery cells 11 or each of the unit cell stacks may have its own vent space surrounded by the metal plate 12 and the heat-resistant filler.

[0091] The cover 121 may be bent outward as the pressure resistance of the vent space increases due to the gas and thermal energy, thereby opening the vent hole 331 upward. At this time, a portion of the cover 121 may be welded to the top plate 33, so that only the cover 121 may be opened without the metal plate 12 itself moving or falling off. By opening the cover 121, high-temperature gas and thermal energy within the housing 3 may be discharged to the outside, preventing a further increase in the temperature of the battery cells 11 and delaying the progression of ignition.

[0092] At this time, the vent holes on the other battery cells other than the ignited battery cell 11 can still be covered with a lid. This prevents the gas and heat energy discharged from the ignited battery cell 11 through the opened vent hole 331 from flowing further into the housing and heating the other battery cells. In addition, the battery cells 11 can be separated from each other by heat insulating pads 13, which prevents heat transfer between the battery cells 11 due to thermal conduction.

[0093] If the metal plate is too thin, the cover is easily damaged and does not adequately prevent the inflow of gas. If the metal plate is too thick, the bending and welding process becomes difficult, and the vent space may not open despite an increase in pressure resistance due to ignition. In this regard, the metal plate may have an appropriate thickness so that it can be easily bent when subjected to a force greater than a predetermined value, yet has sufficient bending rigidity to prevent deformation when subjected to a force less than a predetermined value. For example, the metal plate may have a thickness of 1 mm to 2 mm. Preferably, the metal plate may have a thickness of 1.4 mm to 1.6 mm. By appropriately selecting the thickness as described above, the metal plate can perform both the function of preventing the inflow and the outflow of gas and thermal energy.

[0094] In a battery module according to one embodiment of the present invention, each battery cell 11 has its own vent space insulated from the others by the insulating pad 13. If one of the battery cells 11 catches fire, the cover 121 opens the vent hole 331 to discharge high-temperature gas and thermal energy from the vent space to the outside of the housing 3, the covers attached to the other vent holes prevent the discharged gas and thermal energy from flowing into other vent spaces, and the insulating pad 13 prevents heat propagation by conduction between the battery cells 11. As a result, this embodiment can provide a battery module structure that quickly and selectively discharges heat, prevents heat inflow, and prevents chain reaction fires and thermal runaway due to heat propagation.

[0095] The present invention also provides a battery pack incorporating the battery module and a vehicle structure incorporating the battery pack.

[0096] 18 and 19 show a battery pack incorporating another battery module and a vehicle incorporating the battery pack, respectively, according to an embodiment of the present invention. Referring to these drawings, a plurality of the battery modules (M) may be incorporated into a single pack frame to form a battery pack (P) due to their high voltage and / or high capacity. The plurality of battery modules (M) may be connected in parallel or series to each other by pack bus bars included in the battery pack (P), resulting in a high overall voltage and capacity. The battery pack (P) may be incorporated into an electric vehicle (V) powered by a secondary battery. The battery pack (P) may provide power to the vehicle (V) via a motor incorporated in the vehicle (V). Detailed structures of these battery packs and vehicles are well known to those skilled in the art, and will not be described in detail herein.

[0097] It should be understood that the above-described embodiments are illustrative in all respects and are not limiting, and the scope of the present invention is defined by the following claims rather than the above detailed description. All modifications and variations within the meaning and scope of the following claims, as well as equivalent concepts, should be construed as being included within the scope of the present invention.

[0098] Although the present invention has been described above with reference to illustrative drawings, the present invention is not limited to the embodiments and drawings disclosed in this specification, and various modifications may be made by those skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention are not explicitly described in the above description of the embodiments of the present invention, it is natural that the effects that can be predicted by the configuration should also be recognized. [Explanation of symbols]

[0099] 1 Battery cell stack 11 Battery Cells 111 First seal part 112 Second seal part 113 Electrode Lead 12 metal plates 121 Lid 121a 1st lid part 121b 2nd lid part 13. Heat-insulating pad 2 Busbar Frame 21 Slit 22 Busbar 3. Housing 31 U-frame 311 Insulating film 32 End plate 33 Top Plate 331 Vent hole 331a First vent hole 331b Second vent hole 332 Slit 333 Welded Parts 4. Heat-resistant filler (silicone) M Battery Module P Battery pack V Automobile X length direction Y width direction Z height direction

Claims

1. a battery cell stack formed by stacking a plurality of pouch-shaped battery cells and metal plates in the width direction; a U-frame that is open at the top, front, and rear and that houses the battery cell stack; A pair of end plates covering the front and rear of the U-frame; and a top plate covering the upper part of the U-frame; The top plate is provided with a plurality of vent holes, The metal plate is provided with a plurality of lid portions corresponding to the vent holes, Each of the lid portions protrudes upward through the top plate and is bent to one side in the width direction to cover at least a portion of the area of ​​the vent hole. Battery module.

2. the metal plate is stacked on the other side of each of the battery cells in the width direction; One vent hole is provided on each of the battery cells. The battery module according to claim 1 .

3. the metal plate is stacked on the other side of each of the battery cells in the width direction; A plurality of the vent holes are provided on each of the battery cells. The battery module according to claim 1 .

4. A plurality of the vent holes are provided on each of the battery cells and arranged at intervals in the longitudinal direction. The battery module according to claim 3 .

5. the battery cell stack includes a plurality of unit cell stacks each including a plurality of the battery cells, the metal plate is stacked on the other side of each of the unit cell stacks in the width direction, One vent hole is provided on each of the unit cell stacks. The battery module according to claim 1 .

6. the battery cell stack includes a plurality of unit cell stacks each including a plurality of the battery cells, the metal plate is stacked on the other side of each of the unit cell stacks in the width direction, A plurality of the vent holes are provided on each of the unit cell stacks. The battery module according to claim 1 .

7. A plurality of the vent holes are provided on each of the unit cell stacks and arranged at intervals in the longitudinal direction. The battery module according to claim 6 .

8. A plurality of the vent holes are provided on each of the unit cell stacks and arranged at intervals in the width direction. The battery module according to claim 6 .

9. a heat insulating pad laminated together with the battery cell and the metal plate; The battery module according to claim 1 .

10. The heat insulating pad is laminated on one or the other side of the metal plate in the width direction. The battery module according to claim 9 .

11. The heat insulating pad is interposed between any two of the battery cells adjacent in the width direction. The battery module according to claim 9 .

12. The insulating pad is made of a compressible material. The battery module according to claim 9 .

13. a heat-resistant filler material that fills at least a portion of the space between the battery cell stack and the end plate; The battery module according to claim 1 .

14. The battery cell has first seal portions at both ends in the longitudinal direction thereof, The heat-resistant filler covers the first seal portion. The battery module according to claim 13.

15. The heat-resistant filler includes heat-resistant silicone. The battery module according to claim 13.

16. Each of the lid portions is bent to one side in the width direction, and then a portion thereof is welded to the top plate. The battery module according to claim 1 .

17. The lid portion includes a first lid portion that penetrates the top plate through a predetermined first vent hole and covers a second vent hole that is adjacent to the first vent hole in the width direction. The battery module according to claim 1 .

18. the first lid portion contacts the top plate at one side end of the first vent hole in a width direction; The battery module according to claim 17.

19. The lid portion includes a second lid portion that penetrates the top plate through a slit provided in the top plate and covers the vent hole adjacent to the slit in the width direction. The battery module according to claim 1 .

20. The second cover portion contacts the top plate at one side end portion in the width direction of the slit. The battery module of claim 19.

21. The metal plate has a thickness of 1 mm to 2 mm. The battery module according to claim 1 .

22. The metal plate has a thickness of 1.4 mm to 1.6 mm. The battery module according to claim 21.

23. The battery cell has a second seal portion provided at one end in the height direction thereof, the battery cell stack is arranged so that the second seal portion faces upward; The battery module according to claim 1 .

24. the second sealing portion is provided along one long side in a width direction of one surface in a height direction of the battery cell; The battery module of claim 23.

25. A battery module comprising the battery module according to any one of claims 1 to 24. Battery pack.

26. 26. A battery pack comprising the battery pack of claim 25. car.

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